Filastatin is a nontoxic inhibitor of adhesion to human cells, and it affects multiple Candida species. Filastatin blocks the ability of Candida albicans, and other Candida sp. to bind to polystyrene, and human A549 cell monolayers. Filastatin also blocks biofilm formation and yeast-to-hyphal morphologic transition through inhibition of the hyphal-specific promoter HWP1.